The present technology relates to an etching process using dry etching, a method of manufacturing an electronic device using the etching process, and a method of manufacturing a polarizing plate using the etching process.
In a manufacturing process of an electronic device such as a display unit and an image pickup device, a metal film is patterned to form a wiring pattern. For example, the wiring pattern may be formed as follows. First, a metal film is formed on an entire surface of a substrate, and then a resist film pattern is formed on the metal film using a photolithography technique. Subsequently, the metal film is dry-etched using the resist film as a mask. Subsequently, the resist film is removed to produce a desired wiring pattern. In such a formation method of the wiring pattern, the surface of the metal film is covered by a mask, and the metal film exposed from the mask is scraped in a direction perpendicular to a substrate surface. However, a sidewall of the wiring pattern is exposed to an etching gas atmosphere during the etching. This may easily cause occurrence of so-called side etching in which the sidewall is excessively etched in a horizontal direction with respect to the substrate surface. In particular, a sidewall of a wiring pattern of a corrosion-prone aluminum material may be greatly scraped.
A carbon inclusion generated from the resist film is used as a protective material so that such side etching is suppressed. In a dry etching step using high-density plasma, a carbon inclusion generated from a polymer configuring the resist film is decomposed in the plasma, and adheres to the sidewall of the wiring pattern. Such a carbon inclusion acts as a protective material, so that it is possible to prevent side etching (for example, see Japanese Unexamined Patent Application Publication No. 2009-188224).